The Groups viewport is a great workflow streamlining tool allowing users the ability to easily control multiple items and/or channels within a scene, and also provides a number of functionalities to speed up common tasks, such as setting keyframes for complex hierarchies. Groups also add functionality to 'Replicators' and the 'Light Linking' feature found in modo. Not to be confused with 'Group' Items in the Item List which are a purely organizational construct and Shader Tree 'Groups' which define masks for surface shading as well as to organize the many Shader Tree layers.
To work with groups, one will first need to create a new group using the 'New Group' button on the top of the viewport. When a new group is created it will use the default name 'Group' which can be easily changed by clicking to highlight the name and then pause clicking to edit. Groups can be made up from any number of scene items, including mesh items, cameras, lights, and even locators. Channels can also be part of a group to speed up animation workflows. When in 'Item' mode, items can be added to a group by drag and drop, simply select the item in the 3D viewport you wish to add and click-drag it to the group window and release the mouse button over the group you wish to add the items to. On orange highlight appears in the list to denote where the item will land when dropped. Channels can be added in the same fashion from the 'Channels' viewport.
The viewport itself has a number of controls. The columns on the left allow the user to make changes that affect all items in the Group. The first column affects visibility for items within the group essentially the same way the eye column toggles visibility in the 'Item List'. The second column toggles render visibility; whether or not items appear in rendered output. Note that both these settings can be overridden by the same settings on the individual item's properties forms. For example, if a user has a group containing 20 items, of which 5 were set to 'Yes' for visibility in individual items properties, then toggling the groups visibility would only toggle 15, as the other 5 items settings would override the group settings. Setting the 5 individual items back to 'Default' would return the items back to following the group settings.
The third column when clicked will present a color picker that one can use to change the wireframe color for all items within the group and the fourth column will change the solid display fill color for all items in the group. Changing the display colors of items can be an easy way to visually tell which items are members of which groups in scenes with many items. Individual item settings can be adjusted within the 'Display' viewport when items are selected.
Preceding the group names and item and channel lists are little +/- toggles that unfold/fold list visibility. When the lists are unfolded, individual items can be selected and their respective properties or channel settings can be viewed in the appropriate viewport.
Channels in Groups--
Groups can contain any number of individual channels from any combination of items in the scene. These Individual channels can also be members as many different groups the user wishes. If the visibility of a group containing channels is turned off, then those channels will be hidden in the various channel lists, i.e. the main Channel List viewport, Graph Editor and Channel Links viewport, though Properties are not affected by this setting. If a group containing channels is locked, then the channels cannot be edited anywhere, including the Channel list, Properties viewport or interactively in a 3D viewport with the transform tools.
Group Parenting--
Groups can be parented together, similar to 3D items, just drag a child group and drop onto a parent item, working the same way parenting is performed in the Item List. Instead of inheriting transforms from their parents though, they inherit the group settings from their parent groups. Groups do not need to have any member items or channels either. They can be used as organizational tools. An example would be multiple groups each containing many items. If parented to an empty group and the visibility is switched off on that group, then all the child groups and hence their member items will be hidden in the 3D views.
Group visibility and render channels can also override in the same way as their counterparts on mesh items. So in the above example setting one of the child group's visibility channel to 'Yes' will override the parent setting making all members of the group visible. Conversely if the parent group visibility is set to show member items, then setting a child's visibility channel to 'No' will override that and hide its members. All other children of the parent group will still get their settings from the parent group. This also applies to the group's 'Render', 'Selection' and 'Locking' settings available by the RMB context menu.
Group Drawing Settings--
The 'Wireframe' and 'Fill' columns of the 'Groups' viewport allow easy access to basic display settings, however groups also support the full custom drawing settings available for 3D items. If you look in the 'Display' viewport with a group selected you'll see an “Add Group Draw Options†button which when clicked will display the custom drawing channels used for 3D items (if you've already set a wire or fill color for the group the custom drawing channels will already be available). The difference with setting these channels on a group as opposed to individual items is that the group settings will apply themselves to all items within the group.
Group custom drawing is layered from parent groups to child groups, so settings on parent groups will override any settings on child groups. In order for settings on child groups to be visible custom drawing on any parent groups needs to be disabled in the Display properties viewport by switching off the 'Enable' channel. It is not currently possible for child group custom drawing to override parent settings in the same way as the visibility settings for example.
For all settings the order in which the group appears in the groups viewport is also taken into account. Groups are searched from the top down, when an item is found in a group hierarchy modo looks at the settings on the group containing the item, if that setting is 'Default' it looks up the group hierarchy for a non-default setting. If one is found then that setting is used, otherwise it continues to look through the groups in the viewport from the top down.
Since multiple groups can contain the same items this can be used to very quickly change settings, for example, if two groups contain the same items, one is set to lock member items and make them unselectable and has it's custom drawing set to a dark color to indicate they can't be changed. The other group has the inverse settings applied. Just by dragging either group above the other in the viewport will change the settings applied to the items in the groups, e.g. if the locked group is topmost then all the items will be drawn dark and will be uneditable and not selectable, otherwise the items will be drawn in the other color and can be edited and selected.
Contextual Menu--
RMB clicking on a group will present the user with a number of options as well.
Rename: Will present the user with a popup dialog box that allows the user to rename the highlighted group.
Add Items/Channels: Will add all the currently selected items from the item list or 3D viewport, or channels from the channels viewport.
Select Items/Channels: Will item mode select all the associated items or channels within the group.
Key Items/Channels: Will add a keyframe at the current timeline position for all associated items or channels within the group.
Members Render: Sets if group members are visible in rendered images: "Default" respects item list visibility settings (or parent group settings if applicable), 'Yes' setting enables member items visibility in rendered images, while 'No' disables member items render visibility. When used in conjunction with group parenting, child group settings will override parent settings.
Members Visible: Sets if group members are visible in 3D viewports: "Default" respects item list visibility settings (or parent group settings if applicable), 'Yes' setting enables member items visibility in 3D viewports, while 'No' disables member items visibility in 3D viewports. When used in conjunction with group parenting, child group settings will override parent settings.
Members Selectable: Sets if group members are selectable in 3D viewports: "Default" respects item list settings (or parent group settings if applicable), 'Yes' setting enables member items as selectable in 3D viewports, while 'No' disables selecting of member items in 3D viewports. When used in conjunction with group parenting, child group settings will override parent settings.
Members Locked: Sets if group members are locked from property changes: "Default" respects item list settings (or parent group settings if applicable), 'Yes' setting enables member property modifications, while 'No' disables member property modifications. When used in conjunction with group parenting, child group settings will override parent settings.
Remove Selected Items: Users can select an item in the 3D viewport or ctrl-select multiple items and use the 'Remove Selected Items' command to remove selected items from a group.
Remove Selected Channels: Users can select a channel in the channel viewport or ctrl-select multiple channels and use the 'Remove Selected Channels' command to remove the selected channels from a group.
Remove All Items: Will remove all items from within the group.
Remove All Channels: Will remove all channels from the group.
Remove All: Will remove everything, all items and channels from the group.
Delete: Will delete the group, removing it and its contents from the group viewport.
Keyframing and Selecting Group Members--
Groups can also be used to help with keyframing workflow as well as with item selections. On the Group Properties viewport there are buttons to key items and channels within the selected group (also available via the right click context menu). When keying group items only channels belonging to the items that are already keyed will be affected. Keying channels within a group will add a key at the current time to each member channel, regardless of whether they have been keyed already or not. This becomes more powerful with parented groups and the use of the group Hierarchy buttons also displayed on the Group Properties form. By default only the contents of the currently selected groups will be keyed (or selected), but this behavior can be changed with the Hierarchy type buttons:
None: The default, only keys the contents of the current group(s).
Down: Keys the contents of the current groups and all child groups.
Branch: Keys the contents of the hierarchy branch that the current group resides in
Branch Related: As above but will also key the branches related to the current one, i.e. branches that share a common parent. (An example might be fingers on a hand.)
Root: Keys the contents of the entire hierarchy that the group belongs to.
When a Group contains one or more light items (directional, spot, point or any of the other light types), they can also be used to control the lights overall affect on shading on a surface by surface basis using a Shader in the shader tree with the Llight Linking function. Please reference the Shader Item properties for further information.
Multiple items can act as base Prototypes for Replicators when set into a Group, allowing for greater variety in replicated objects. To use multiple mesh items as prototypes for a single replicator, first create a group that contains all the different mesh layers, once a Replicator has been created, the Group name will appear in the replicators 'Prototype' drop down list. When specified, the replicator will randomly grab objects from the group for each 'replica'. Please reference the Replicators page of the documentation for further information.
